Geology Commons^™

System-Scale Patterns Of Karst Ventilation In A Mediterranean Karst Massif And Their Implications For The Subsurface Thermal Regime, José Luis Yanes, Francisco Moral

International Journal of Speleology

Karst systems are heterogeneous environments in which water flow is commonly assumed to control subsurface thermal dynamics. However, the role of air circulation at the system scale remains poorly constrained. This study presents a characterization of the thermal expression of ventilation processes in a western Betic Range (southern Spain) karst massif, based on the continuous monitoring of air temperature in multiple conduits distributed along an altitudinal gradient, combined with the analysis of external atmospheric conditions. Results show that ventilation is strongly seasonal and controlled by the interaction between thermal gradients, transient atmospheric variations and system geometry. The observations reveal recurrent …

Calcite Spar Of Kryštálová Cave (Slovakia): Insights Into Formation Conditions From Fluid Inclusions, Stable Isotopes, And Noble Gases, Petronela Ševčíková, Yuri Dublyansky, Stanislava Milovská, László Palcsu, Marjan Temovski, Kata Molnár, Gabriella I. Kiss, Mário Olšavský, Pavel Herich, Gabriella Koltai, Christoph Spötl

International Journal of Speleology

Phreatic calcite spar is an infrequently used yet promising archive for paleohydrology, a diagnostic tool for speleogenesis, and a robust geothermometer. In this study, we investigated phreatic calcite from Kryštálová cave (Malá Fatra Mts., Slovakia) to constrain its formation conditions, reconstruct the composition of its parent fluid, determine precipitation temperatures, and assess its potential for paleohydrology. Fluid-inclusion microthermometry and stable isotope analyses of inclusion water indicate that calcite precipitated at 45-80°C from a meteoric fluid (δ²H_meas = -87.4 to -84.4‰; δ¹⁸O_calc = -12.2 to -11.8‰) with a purely crustal noble gas signature. Stable …

Quality Assurance Project Plan - Spokane River Pfas Study, Chad Pritchard

EWU PFAS Research Collection

Assessing the impacts of poly- and perfluoroalkyl substances (PFAS) contamination across multiple aquifers and multiple sources requires a detailed understanding of the hydrogeologic framework to quantifiably determine PFAS sources. The West Plains of eastern Washington is an ideal natural laboratory to study the fate and transport of PFAS because the general geohydrologic framework has been established and collaboration with several related PFAS projects will maximize the use of grant funds. This project will help the population, environment, and commercial entities of the West Plains by building a transport model, delineating PFAS contamination, and using unique PFAS distribution at different locations …

Karst Hydrogeologic Framework And Factors Contributing To Flooding In Burgin, Kentucky, Charles Taylor, Junfeng Zhu, Matthew Carmichael, Hudson J. Koch

KGS Publications and Maps

This report examines the karst hydrogeologic setting and drainage characteristics that are thought to contribute to frequent severe flooding in the city of Burgin in Mercer County, Kentucky. Burgin is located at the eastern end of an approximately 4.5 mi² mapped karst groundwater basin in the Ordovician limestone aquifer system in the Inner Bluegrass karst region. Flooding occurs within a streamless 1.4 mi² dry karst valley where almost all channelized surface runoff has been captured by sinkholes and sinking stream segments and diverted underground by con­duit piracy. The only natural outlet for water exiting from the karst valley and larger …

Hydrogeophysical Assessment Of Groundwater And Saltwater–Freshwater Interface In A Quaternary– Neogene Coastal Aquifer, Kilwa Kisiwani Island, Southeast Tanzania, Simon R. Melchioly

Tanzania Journal of Science

This study aims to identify and explore new potential sites of groundwater resources using geophysical methods, and to demarcate the depth to the saltwater-freshwater interface. Kilwa Kisiwani Island is geologically covered mostly by Neogene and Quaternary alluvial sediments, sand and gravel. The geophysical techniques employed during the research include Vertical Electrical Sounding (VES), Electrical Resistivity Tomography (ERT), and Transient Electromagnetics (TEM). The Island has the potential for groundwater occurrences, but the layer with fresh water is shallow and thin. Out of the 18 VES sites, 2 (11%) points have shown non-potential, but the remaining 16 (89%) of the VES sites …

Implementation Of A Practical Sharp Interface Saltwater Intrusion Model To Assess Future Sea-Level Impacts, Alexandra G. Defalco

All Theses

Rising sea levels caused by global warming exacerbate saltwater intrusion, the inland movement of seawater into coastal aquifers. These processes increase susceptibility to freshwater contamination, surface flooding, and infrastructure damage. Numerical models are utilized to assess hazards to coastal aquifers on a regional scale.

The U.S. Navy is currently developing a robust, reduced-order groundwater modeling platform, SWI6, that uses the sharp interface approach to approximate the location of the freshwater-saltwater interface to define the extent of saltwater intrusion within an aquifer. Featuring compatibility with MODFLOW 6 unstructured grid formats and the Newton-Raphson formulation for better solution stability, SWI6 improves upon …

Characterizing Microplastics In Flood Sediments After Hurricane Helene In Asheville, North Carolina, Abigail Sgan

All Theses

Microplastics are contaminants of emerging concern whose ubiquity across natural environments results in their involvement in many kinds of natural processes, including transportation and deposition in natural systems. The purpose of this thesis is to characterize microplastics and determine the mechanisms that affect their distribution, transport, and sequestration within known Hurricane Helene flood deposits in fluvial and Southern Appalachian wetland environments after Hurricane Helene in Asheville, North Carolina. Four fluvial and four Southern Appalachian wetland environments were sampled after Hurricane Helene. Samples collected in fluvial environments were taken as grab samples from surficial sandy flood deposits left behind by flooding …

Hydrogeochemical Characterization Of Groundwater In Fractured Crystalline Basement Aquifers In Dodoma, Central Tanzania: Implications On Water Quality For Domestic And Irrigation Applications, George J. Ishabairu, Simon R. Melchioly, Charles H. Kasanzu, Gabriel D. Mulibo

Tanzania Journal of Science

Assessment of groundwater hydrogeochemistry characteristics of aquifers plays a vital role in establishing water quality status and its suitability for human and industrial use. The main objective of this research was to carry out hydrogeochemical characterization of groundwater and assess its impacts on water quality and spatial variability of groundwater geochemistry in Dodoma, Tanzania. The methods used include groundwater sampling, laboratory analysis to determine physico- chemical parameters and data processing to classify the groundwater hydrochemical facies. The results show that the average value for pH is 7.2, for electrical conductivity (EC) is 1108 µS/cm and for total dissolved solids (TDS) …

Transboundary Groundwater Flow Between Niger And Nigeria In The Iullemeden Aquifer System, Gare Ambrose-Igho

UNLV Theses, Dissertations, Professional Papers, and Capstones

Groundwater is important in regions where water resources are not abundantly distributed such as arid and semi-arid regions. In many countries in Africa, groundwater serves as the most reliable source of water supply and supports over 50% of the African population. Groundwater is stored in underground water-bearing permeable rocks, rock fractures, or unconsolidated materials known as aquifers. Groundwater can be transboundary, meaning it crosses international political boundaries between two or more sovereign states. Transboundary aquifers are prone to overexploitation that depletes the groundwater resource and can cause a lowering of the water table and possible ground subsidence. Overexploitation in transboundary …

Analyzing Surface Water And Groundwater Interactions From Pfas Contamination In The West Plains Region Of Spokane County, Jerusha R. Hampson

2026 Symposium

The West Plains region of Spokane County has been significantly impacted by PFAS contamination due to the decades-long use of aqueous film-forming foam (AFFF) for firefighting training at both Fairchild Air Force Base (FAFB) and the Spokane International Airport (SIA). Groundwater contamination is significant, but surface waters are impacted by the contamination as well. Groundwater flows to the north and east, meaning surface water bodies that make up the northern and eastern boundaries (Deep Creek, Hangman Creek, and the Spokane River) can be impacted by PFAS contamination. The West Plains aquifer system is complex but combining data about aquifer flow …

Preliminary Geologic Assessment And Pfas Occurrence In Western Cheney, Washington, Sydney Frandsen

2026 Symposium

In 2021 Cheney Water Well #5 was closed due to toxic per- and polyfluoroalkyl substances (PFAS) levels above the current State Action Limits and the National Drinking Water Protection Act (https://www.cityofcheney.org/207/Water), which is a concern since PFAS has been associated to types of cancer, birth defects, and other negative human and environmental health concerns (https://doh.wa.gov/communityand-environment/contaminants/pfas). The City of Cheney also tested two downgradient deep-groundwater-wells (Cheney wells #6 and 7) and halted investigation due to the wells being below state and federal drinking water standards. However, a local resident’s shallow groundwater well tested to be above federal and state levels of …

Exploring Alternate Methods Of Flood Output Estimation During Natural Disasters, Finley Gardner

Honors College Theses

In April of 2025, extreme flooding damaged many homes and buildings of people across Kentucky. The Federal Emergency Management Agency (FEMA) produces maps that show the potential for flooding in areas around water bodies, but many of the April flooding damaged areas were well outside of the FEMA classification zones. The main purpose of this thesis research was to create an accurate model of potential flood extent in Kentucky and compare it to FEMA maps. This model did not require extensive computing power and produced a map that accurately depicted flood extent through the use of Digital Elevation Model (DEM) …

Response Of Botovskaya Cave To Local And Regional Environmental Dynamics, Jade Margerum, Oksana Gutareva, Franziska Lechleitner, Maria Box, Stuart Umbo, Anton Vaks, Hanno Meyer, Aleksandr Kononov, Aleksander Osintsev, Dimitri Sokol'nikov, Norbert Marwan, Ola Kwiecien, Sebastian Breitenbach

International Journal of Speleology

Speleothems from caves in near-permafrost regions can provide unique insights into the climatic history of temperature-sensitive environments. These regions are often remote and only seasonally accessible, which makes cave monitoring – a requirement for speleothem-based proxy interpretation – challenging. We document ventilation, the infiltration regime, and the isotopic composition of dripwater in Botovskaya Cave in southern Siberia, a host to speleothems previously used to reconstruct Quaternary permafrost dynamics in continental Eurasia. We explore surface and cave temperature records, cave air CO₂ concentration data and stable isotopes in precipitation and dripwater and evaluate infiltration conditions and the sensitivity of speleothems …

No Name Ditch Filter Request, Chad Pritchard, Sonja Durr

EWU PFAS Research Collection

This is a one-page request showing the need for filtration at No Name Ditch at the SE corner of Fairchild Air Force Base (FAFB), West Plains, Spokane County, Washington.  Surface water levels in the ditch and stormwater ponds that feed the system can exceed 20,000 ppt for PFOS while groundwater can be up to 2,000 ppt for PFOS, per a remedial investigation report for FAFB in 2025.  The federal drinking water standard for PFOS is 4 ppt. While surface water and stormwater are not regulated for PFAS levels, these polluted waters enter the groundwater just off base and likely contaminate …

Nebraska Statewide Groundwater-Level Monitoring Report 2025, Aaron R. Young, Mark E. Burbach, Sue Olafsen Lackey, Robert Matthew Joeckel, Jeffrey Westrop

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Hydrogeochemical And Redox Controls On Nitrate And Arsenic Co-Occurrence In The Western Kansas High Plains Aquifer (Usa): A Composite Health Risk Assessment And The Case For Risk-Informed Private Well Governance, Jonathan Kuffour Owusu

Master's Theses or Doctor of Nursing Practice

Fifty-one private domestic wells across western Kansas were sampled to quantify nitrate and arsenic occurrence, identify geochemical controls, and evaluate carcinogenic and non-carcinogenic health risks for adult and child receptors in a region where groundwater serves as the primary drinking water source with no routine regulatory oversight. Samples were analyzed for major ions, nutrients, and trace elements by ICP-MS, ion chromatography, and UV-Vis spectrophotometry. Shapiro-Wilk testing confirmed non-normal distributions for both contaminants; inter-county comparisons were therefore conducted using Kruskal-Wallis tests with Dunn's post-hoc correction. Health risk was quantified via chronic daily intake (CDI), hazard quotient (HQ), HQ-based Water Quality Index …

The Geomorphology And Hydrogeology Of Pre-Restoration West Fork Teanaway River, Wa, Usa, Shana M. Egan

All Master's Theses

The West Fork Teanaway (WFT) River in Kittitas County, WA is an entrenched bedrock river channel with disturbed floodplain geomorphology and degraded riparian ecology. Two stream restoration approaches, “stage 0” valley bottom reset and engineered logjam installation, will be installed at the WFT in summer 2026 by collaborators at the Washington State Department of Fish and Wildlife and Mid-Columbia Fisheries Enhancement Group. The objective of this study was to constrain the pre-restoration geomorphic and hydrologic conditions of the WFT. The WFT has an unconsolidated floodplain aquifer of predominantly coarse-grained fluvial deposits. Monitoring of groundwater and surface water levels began in …

Using Grounded Iceberg Wake Patterns To Interpret Catastrophic Flood Events In Southcentral Alaska, Jana K. Macinnis

All Master's Theses

Catastrophic flood events such as landslide tsunamis and jökulhlaups in glaciated areas can transport and strand icebergs, which obstruct the flow of floodwaters and leave a unique and recognizable grounded iceberg wake pattern in the sediment surface. Grounded iceberg wake patterns (GIWs) were identified at the two study areas in Southcentral Alaska; the outwash plain of a 1967 landslide tsunami at the Grewingk Glacier and proglacial lake, and the Matanuska River valley which experienced an unrecorded jökulhlaup in recent geological times. From these sites, 110 GIWs were identified through visual interpretation of lidar imagery and characterized by measuring their geometry, …

Flood-Season Surface Water-Groundwater Interactions Across Distinct Geomorphic Units In A Yellow River Great Bend Tributary Basin, Yinlong Wang, Ruizhong Gao, Debin Jia, Xixi Wang, Tingxi Liu, Xiaomin Liu, Shiming Bai

Civil & Environmental Engineering Faculty Publications

Surface water-groundwater interactions are complex in the Great Bend region of the Yellow River. Clarifying water exchange and source differences among geomorphic units is important for understanding regional hydrological processes and improving water resources management. In this study, the Wulanmulun River Basin, a typical tributary of the Yellow River, was selected as the study area. A total of 90 water samples were collected, including 25 river water samples, 43 groundwater samples, and 22 precipitation samples. Gibbs diagrams, multivariate statistical analysis, PMF, and MixSIAR models were used to investigate the hydrochemical and isotopic characteristics, source contributions, and transformation relationships of surface …

Modeling The Effects Of Subsurface Tile Drainage On Atrazine And Nitrate Transport In Till Soils Of Iowa, Madison Hobbs

West Chester University Graduate Theses, Dissertations, and Final Projects

Tile drainage design influences groundwater flow pathways, residence time, and agrochemical transport in agricultural soils. This study evaluates how differences in drainage design affect subsurface flow behavior and contaminant transport in glacial till soils. A groundwater model was developed to compare conventional and controlled drainage systems with a shallow drainage system, and particle tracking was used to examine flow paths and residence times.

The results show that tile drainage creates distinct shallow and deeper flow pathways. In the conventional and controlled model, 88% of particles were captured by drains, while 12% reached the general head boundary. The shallow system drains …

Last Glacial Maximum And Late Glacial Aeolian Sand Activity, South-Central Indiana, Usa, H. M. Loope, J. L. Antinao, P.R. Hanson, P. M. Jacobs, D. A. Grimley

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Report 17—Revisions To The Articles Of Organization And Procedure Of The Commission On Stratigraphic Nomenclature Of The Americas, Lynn T. Dafoe, Robert B. Macnaughton, Marie-Perre Aubry, Carlton E. Brett, James R. Lehane, Fernando Núñez-Useche, Randall C. Orndorff, Frank Brunton, Lucy E. Edwards, Richard H. Fluegeman, Howard Harper, Robert Matthew Joeckel, Norman P. Lasca, B. H. Tew

Conservation and Survey Division: Faculty and Staff Publications

Several revisions to the Articles of Organization and Procedure for the North American Commission on Stratigraphic Nomenclature have been adopted following the 75th, 79th, and 80th annual meetings of the Commission in 2020, 2024 and 2025, respectively. Of these, the most substantial change was revision of Article III regarding membership composition of the Commission and the addition of new member organizations from Central and South America and the Caribbean region. As a result, the Commission also voted to change its name to be more inclusive of the expanding membership, with approval of the name: Commission on Stratigraphic Nomenclature of the …

Spatiotemporal Dynamics Of Mountain Front Recharge Flow Paths And Their Contribution To Alluvial Aquifer Water Supply, Mikaela Bollag-Miller

Graduate Student Theses, Dissertations, & Professional Papers

Mountain Front Recharge (MFR) is a critical recharge source for alluvial basin aquifers throughout the Intermountain West, yet the spatial and temporal dynamics of distinct recharge pathways remain poorly constrained. This study investigates the seasonal and spatial dynamics of MFR pathways and evaluates their impact on the Missoula Aquifer, a sole-source alluvial aquifer in western Montana, USA. MFR includes both surface-water inflows from mountain areas and Mountain Block Recharge (MBR), the groundwater contribution to the basin aquifer. A valley-scale water balance was employed to estimate first-order contributions and temporal fluctuations of MBR flow paths. A three-layer steady-state MODFLOW groundwater model …

Assessing Glacial Mass Change And Its Impact On Water Resources In Parts Of The Himalayas Using Satellite Remote Sensing, Kriti Panta

Theses and Dissertations

This study investigates long-term changes in terrestrial water storage and their impact on hydrological processes in glacier-fed regions of Nepal. The study focuses on the central to eastern Himalayan region, including major river basins within the Koshi system. Multiple datasets, including the Gravity Recovery and Climate Experiment (GRACE) and GRACE follow-on (GRACE-FO) missions satellite data, the Global Land Data Assimilation System (GLDAS) products, and in situ streamflow data, were used for the period 2002–2019. Terrestrial Water Storage Anomaly (TWSA) derived from GRACE data shows a strong decreasing trend over time, indicating significant water storage loss across the study area. Soil …

Investigating Phosphorus Load Trends And Driving Factors In Illinois Watersheds Using Machine Learning Algorithms, Hannah Lartey

Theses and Dissertations

Phosphorus (P) pollution in Illinois watersheds has become a significant water quality concern. Recent studies have shown increasing concentrations in streams and rivers, leading to eutrophication, which damages aquatic ecosystems and threatens human health. This study examines temporal trends in total phosphorus loads across 79 monitoring stations in Illinois from 1979 to 2020 and identifies the main environmental factors that influence P load variability. Trend analyses were conducted using the nonparametric Mann-Kendall and Sen’s slope methods. GIS-based climate, hydrology, and soil property datasets were assembled for each monitoring station. These datasets were used to build machine learning models using the …

A Geospatial Assessment Of Groundwater Salinization In A Multi-Aquifer System: Durango, Mexico, Juan Lopez-Sierra

Graduate Theses/Dissertations

Groundwater salinization poses a critical environmental concern for water resource sustainability in arid and semi-arid regions. This study evaluates spatial and temporal patterns of groundwater salinity across the state of Durango, Mexico, using total dissolved solids (TDS), sodium adsorption ratio (SAR), as salinity indicators and nitrate-nitrogen (NO₃–N) as an anthropogenic indicator. Groundwater quality data were obtained from (CONAGUA), a Mexican water agency. To assess salinity variations with respect to time, while minimizing interannual sampling bias, two multi-year sampling periods were selected: 2012-2013, and 2020-2021. Final datasets consisted of 122 wells for 2012–2013 and 131 wells for 2020–2021. The wells were …

Hydrothermal Vents In Sulfuric Acid Speleogenesis Karst: Isolated Feeders With Pristine Hypogenic Water Or Interconnected Conduits With Rapid Flow And Recycled Water?, Jakub Mareš, Marek Audy, Serban M. Sarbu, Jan Kukačka, Romeo Eftimi, Jiří Bruthans

International Journal of Speleology

Underwater connectivity and flow paths in the saturated zone of hypogenic sulfuric acid speleogenesis (SAS) karst remain unclear, despite sustained research over the past 30 years. Being regarded as sources of pristine H₂S-charged water, narrow inflow conduits called "feeders" are typically considered primary sources of water and hotspots of speleogenesis. In southeastern Albania, there is a newly discovered active SAS karst system comprising numerous caves and springs. Tracer tests were conducted to investigate the connection of these caves to the surrounding springs and to characterize the flow paths. The results show that water flows from cave lakes to …

Aquifer Distribution In Lukobe Ward, Morogoro Municipality, Tanzania: Mapped Resources For Sustainable Water Access, Kelvin K. Kayuni

Tanzania Journal of Science

In response to the ongoing challenges posed by the scarcity of reliable fresh-water sources in Lukobe Ward, Morogoro Municipality, Tanzania, this study applied an integrated approach that combines geospatial and geophysical datasets to identify previously undocumented aquifers. The datasets utilized include an apparent density map generated from high-resolution GGMPlus satellite gravity data, a geological map (Quarter Degree Sheet 183), a water drainage map, and a slope map created from a digital elevation model (DEM). The analysis successfully identified four unconfined, saprolitic aquifers in the study area, designated as aquifers A, B, C, and D. These aquifers span areas of 12.2 …

Engineering Risk And Indigenous Resilience Toward Intelligent Decision Support For Mining In Ancestral Lands, Izech Brian O. Edwin, King Harold A. Recto

Electronics, Computer, and Communications Engineering Faculty Publications

Mining within ancestral territories reveals an ongoing conflict between technical viability and Indigenous consent. This collaborative study, conducted by an engineering scholar and a policy researcher of Indigenous heritage in Benguet among the Ibaloi and Kankanaey peoples, investigates how risk transparency and policy alignment can bridge existing divides, while formulating principles applicable to other Indigenous mining contexts. The study provides an initial evaluation of the feasibility of a proposed large-scale mining operation within a risk-informed, data-driven governance framework. Three elements of engineering risk were assessed utilizing literature-derived and proxy parameters: (1) Land degradation is indicated by a Soil Productivity Index …

Groundwater Arsenic Contamination In The Oro Grande Wash, Dalila Boice

Electronic Theses, Projects, and Dissertations

This study investigates the distribution of naturally occurring arsenic in groundwater within the Oro Grande Wash in San Bernardino County, California. Depth-discrete groundwater quality data were collected over multiple years using nested and Westbay monitoring wells. Water quality results showed higher levels of arsenic in the deeper aquifers, ranging between 600 feet and 1,000 feet below ground surface. Arsenic levels in these regions reached as high as 66 µg/L. At roughly 800 feet and below, water quality data from the wells reveal that arsenic concentrations exceeded the 10 µg/L maximum contaminant level (MCL) in 87% of cases. These data provide …